This invention relates to an apparatus for discontinuous mixing of at least two materials, at least one of which is a liquid. The present invention relates, more particularly to such an apparatus which includes a container and a mixer disposed in the container, the mixer having a rotor drivable at high speed through a shaft and a stator, which are provided with teeth which are positioned on mutually concentric circles and move past one another to form shearing slots.
An apparatus of this kind is known from the book by Kolln-Engels entitled "Betriebshandbuch der Lackherstellung, Apparate, Maschinen, Gerate", (Operational Handbook of Paint Manufacture, Apparatus, Machinery, and Devices), 1959, pp. 128 and 129. In the book, a so-called rod cage mixer is described, which is provided with a rotor having a circle of fixed rods mounted around it, by means of which the materials to be mixed are beaten. This known apparatus is very well suited for the distribution of powdered components, which can also contain larger solid conglomerates, in liquids. Nevertheless, when the consistency increases, these known apparatus have been no longer usable, because they are unable to provide the necessary total flow for the materials to be mixed. In order to increase the beating effect, additional fixed or even counter-rotating rod systems have been provided. This known design is of a complicated construction however and extremely sensitive. In addition, the apparatus thus constructed does not ensure satisfactory circulation of the entire contents of the container.
In view of these problems, it has thus far remained conventional to use mixers for mixing, i.e., for dispersal of solids in liquids and for mixing of liquids in liquids, which are provided with a disk mounted on a drivable shaft and with teeth provided along its outer edge, as taught for example by U.S. Pat. No. 2,651,582 and, in an improved form, by German Auslegeschrift 1,186,039.